“Active Boost technology from AMS changes the game because it enables NFC to become a ‘plug and play’ function for any device with a microSD, SD or SIM card slot,” says AMS’ Mark Dickson.

AMS: No external booster antenna needed with AS3922’s Active Boost

Analog semiconductor specialist AMS has announced the AS3922, an active tag analog front end (AFE) that can be used with a secure element to add contactless payment capabilities to any device with a microSD, SD card or SIM card slot as well as “other space-constrained carrier devices”.

The AS3922 comes with an analog contactless bridge (ACLB) interface for communication with a secure element and uses AMS’s “Active Boost” technology to eliminate the need for an external booster antenna.

“The AS3922 emulates an ISO14443A/B tag through active transmission of the tag’s response in sync with the reader’s carrier field,” says AMS. “This overcomes the difficulties with using conventional passive load modulation in a microSD or microSIM card, a device with a very small antenna and — in a mobile phone — operating in a harsh environment.

“The use of an AS3922 AFE provides for tag-to-reader communication at coupling factors one order of magnitude lower than is possible using conventional methods.”

The AS3922 also features antenna auto tuning (AAT) technology, Q factor adjustment, low-impedance output drivers with adjustable output power, and can emulate Sony FeliCa as well as the ISO14443A and B contactless card standards.

CONTEXT: A block diagram shows how the AS3922 fits in. Click to enlarge.

“Previous SIM or microSD card-based NFC products needed an external booster antenna, which is not user friendly or robust due to its extended antenna,” says AMS’s Mark Dickson. “Active Boost technology from AMS changes the game because it enables NFC to become a ‘plug and play’ function for any device with a microSD, SD or SIM card slot.”

The AS3922 is available in volume today and a demonstration board for evaluating the solution is available on request from AMS.